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-rw-r--r--modules/hostmatcher/hostmatcher.go161
-rw-r--r--modules/hostmatcher/hostmatcher_test.go161
-rw-r--r--modules/hostmatcher/http.go69
3 files changed, 391 insertions, 0 deletions
diff --git a/modules/hostmatcher/hostmatcher.go b/modules/hostmatcher/hostmatcher.go
new file mode 100644
index 00000000..10693103
--- /dev/null
+++ b/modules/hostmatcher/hostmatcher.go
@@ -0,0 +1,161 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package hostmatcher
+
+import (
+ "net"
+ "path/filepath"
+ "strings"
+)
+
+// HostMatchList is used to check if a host or IP is in a list.
+type HostMatchList struct {
+ SettingKeyHint string
+ SettingValue string
+
+ // builtins networks
+ builtins []string
+ // patterns for host names (with wildcard support)
+ patterns []string
+ // ipNets is the CIDR network list
+ ipNets []*net.IPNet
+}
+
+// MatchBuiltinExternal A valid non-private unicast IP, all hosts on public internet are matched
+const MatchBuiltinExternal = "external"
+
+// MatchBuiltinPrivate RFC 1918 (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) and RFC 4193 (FC00::/7). Also called LAN/Intranet.
+const MatchBuiltinPrivate = "private"
+
+// MatchBuiltinLoopback 127.0.0.0/8 for IPv4 and ::1/128 for IPv6, localhost is included.
+const MatchBuiltinLoopback = "loopback"
+
+func isBuiltin(s string) bool {
+ return s == MatchBuiltinExternal || s == MatchBuiltinPrivate || s == MatchBuiltinLoopback
+}
+
+// ParseHostMatchList parses the host list HostMatchList
+func ParseHostMatchList(settingKeyHint, hostList string) *HostMatchList {
+ hl := &HostMatchList{SettingKeyHint: settingKeyHint, SettingValue: hostList}
+ for _, s := range strings.Split(hostList, ",") {
+ s = strings.ToLower(strings.TrimSpace(s))
+ if s == "" {
+ continue
+ }
+ _, ipNet, err := net.ParseCIDR(s)
+ if err == nil {
+ hl.ipNets = append(hl.ipNets, ipNet)
+ } else if isBuiltin(s) {
+ hl.builtins = append(hl.builtins, s)
+ } else {
+ hl.patterns = append(hl.patterns, s)
+ }
+ }
+ return hl
+}
+
+// ParseSimpleMatchList parse a simple matchlist (no built-in networks, no CIDR support, only wildcard pattern match)
+func ParseSimpleMatchList(settingKeyHint, matchList string) *HostMatchList {
+ hl := &HostMatchList{
+ SettingKeyHint: settingKeyHint,
+ SettingValue: matchList,
+ }
+ for _, s := range strings.Split(matchList, ",") {
+ s = strings.ToLower(strings.TrimSpace(s))
+ if s == "" {
+ continue
+ }
+ // we keep the same result as old `matchlist`, so no builtin/CIDR support here, we only match wildcard patterns
+ hl.patterns = append(hl.patterns, s)
+ }
+ return hl
+}
+
+// AppendBuiltin appends more builtins to match
+func (hl *HostMatchList) AppendBuiltin(builtin string) {
+ hl.builtins = append(hl.builtins, builtin)
+}
+
+// AppendPattern appends more pattern to match
+func (hl *HostMatchList) AppendPattern(pattern string) {
+ hl.patterns = append(hl.patterns, pattern)
+}
+
+// IsEmpty checks if the checklist is empty
+func (hl *HostMatchList) IsEmpty() bool {
+ return hl == nil || (len(hl.builtins) == 0 && len(hl.patterns) == 0 && len(hl.ipNets) == 0)
+}
+
+func (hl *HostMatchList) checkPattern(host string) bool {
+ host = strings.ToLower(strings.TrimSpace(host))
+ for _, pattern := range hl.patterns {
+ if matched, _ := filepath.Match(pattern, host); matched {
+ return true
+ }
+ }
+ return false
+}
+
+func (hl *HostMatchList) checkIP(ip net.IP) bool {
+ for _, pattern := range hl.patterns {
+ if pattern == "*" {
+ return true
+ }
+ }
+ for _, builtin := range hl.builtins {
+ switch builtin {
+ case MatchBuiltinExternal:
+ if ip.IsGlobalUnicast() && !ip.IsPrivate() {
+ return true
+ }
+ case MatchBuiltinPrivate:
+ if ip.IsPrivate() {
+ return true
+ }
+ case MatchBuiltinLoopback:
+ if ip.IsLoopback() {
+ return true
+ }
+ }
+ }
+ for _, ipNet := range hl.ipNets {
+ if ipNet.Contains(ip) {
+ return true
+ }
+ }
+ return false
+}
+
+// MatchHostName checks if the host matches an allow/deny(block) list
+func (hl *HostMatchList) MatchHostName(host string) bool {
+ if hl == nil {
+ return false
+ }
+
+ hostname, _, err := net.SplitHostPort(host)
+ if err != nil {
+ hostname = host
+ }
+ if hl.checkPattern(hostname) {
+ return true
+ }
+ if ip := net.ParseIP(hostname); ip != nil {
+ return hl.checkIP(ip)
+ }
+ return false
+}
+
+// MatchIPAddr checks if the IP matches an allow/deny(block) list, it's safe to pass `nil` to `ip`
+func (hl *HostMatchList) MatchIPAddr(ip net.IP) bool {
+ if hl == nil {
+ return false
+ }
+ host := ip.String() // nil-safe, we will get "<nil>" if ip is nil
+ return hl.checkPattern(host) || hl.checkIP(ip)
+}
+
+// MatchHostOrIP checks if the host or IP matches an allow/deny(block) list
+func (hl *HostMatchList) MatchHostOrIP(host string, ip net.IP) bool {
+ return hl.MatchHostName(host) || hl.MatchIPAddr(ip)
+}
diff --git a/modules/hostmatcher/hostmatcher_test.go b/modules/hostmatcher/hostmatcher_test.go
new file mode 100644
index 00000000..c7818474
--- /dev/null
+++ b/modules/hostmatcher/hostmatcher_test.go
@@ -0,0 +1,161 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package hostmatcher
+
+import (
+ "net"
+ "testing"
+
+ "github.com/stretchr/testify/assert"
+)
+
+func TestHostOrIPMatchesList(t *testing.T) {
+ type tc struct {
+ host string
+ ip net.IP
+ expected bool
+ }
+
+ // for IPv6: "::1" is loopback, "fd00::/8" is private
+
+ hl := ParseHostMatchList("", "private, External, *.myDomain.com, 169.254.1.0/24")
+
+ test := func(cases []tc) {
+ for _, c := range cases {
+ assert.Equalf(t, c.expected, hl.MatchHostOrIP(c.host, c.ip), "case domain=%s, ip=%v, expected=%v", c.host, c.ip, c.expected)
+ }
+ }
+
+ cases := []tc{
+ {"", net.IPv4zero, false},
+ {"", net.IPv6zero, false},
+
+ {"", net.ParseIP("127.0.0.1"), false},
+ {"127.0.0.1", nil, false},
+ {"", net.ParseIP("::1"), false},
+
+ {"", net.ParseIP("10.0.1.1"), true},
+ {"10.0.1.1", nil, true},
+ {"10.0.1.1:8080", nil, true},
+ {"", net.ParseIP("192.168.1.1"), true},
+ {"192.168.1.1", nil, true},
+ {"", net.ParseIP("fd00::1"), true},
+ {"fd00::1", nil, true},
+
+ {"", net.ParseIP("8.8.8.8"), true},
+ {"", net.ParseIP("1001::1"), true},
+
+ {"mydomain.com", net.IPv4zero, false},
+ {"sub.mydomain.com", net.IPv4zero, true},
+ {"sub.mydomain.com:8080", net.IPv4zero, true},
+
+ {"", net.ParseIP("169.254.1.1"), true},
+ {"169.254.1.1", nil, true},
+ {"", net.ParseIP("169.254.2.2"), false},
+ {"169.254.2.2", nil, false},
+ }
+ test(cases)
+
+ hl = ParseHostMatchList("", "loopback")
+ cases = []tc{
+ {"", net.IPv4zero, false},
+ {"", net.ParseIP("127.0.0.1"), true},
+ {"", net.ParseIP("10.0.1.1"), false},
+ {"", net.ParseIP("192.168.1.1"), false},
+ {"", net.ParseIP("8.8.8.8"), false},
+
+ {"", net.ParseIP("::1"), true},
+ {"", net.ParseIP("fd00::1"), false},
+ {"", net.ParseIP("1000::1"), false},
+
+ {"mydomain.com", net.IPv4zero, false},
+ }
+ test(cases)
+
+ hl = ParseHostMatchList("", "private")
+ cases = []tc{
+ {"", net.IPv4zero, false},
+ {"", net.ParseIP("127.0.0.1"), false},
+ {"", net.ParseIP("10.0.1.1"), true},
+ {"", net.ParseIP("192.168.1.1"), true},
+ {"", net.ParseIP("8.8.8.8"), false},
+
+ {"", net.ParseIP("::1"), false},
+ {"", net.ParseIP("fd00::1"), true},
+ {"", net.ParseIP("1000::1"), false},
+
+ {"mydomain.com", net.IPv4zero, false},
+ }
+ test(cases)
+
+ hl = ParseHostMatchList("", "external")
+ cases = []tc{
+ {"", net.IPv4zero, false},
+ {"", net.ParseIP("127.0.0.1"), false},
+ {"", net.ParseIP("10.0.1.1"), false},
+ {"", net.ParseIP("192.168.1.1"), false},
+ {"", net.ParseIP("8.8.8.8"), true},
+
+ {"", net.ParseIP("::1"), false},
+ {"", net.ParseIP("fd00::1"), false},
+ {"", net.ParseIP("1000::1"), true},
+
+ {"mydomain.com", net.IPv4zero, false},
+ }
+ test(cases)
+
+ hl = ParseHostMatchList("", "*")
+ cases = []tc{
+ {"", net.IPv4zero, true},
+ {"", net.ParseIP("127.0.0.1"), true},
+ {"", net.ParseIP("10.0.1.1"), true},
+ {"", net.ParseIP("192.168.1.1"), true},
+ {"", net.ParseIP("8.8.8.8"), true},
+
+ {"", net.ParseIP("::1"), true},
+ {"", net.ParseIP("fd00::1"), true},
+ {"", net.ParseIP("1000::1"), true},
+
+ {"mydomain.com", net.IPv4zero, true},
+ }
+ test(cases)
+
+ // built-in network names can be escaped (warping the first char with `[]`) to be used as a real host name
+ // this mechanism is reversed for internal usage only (maybe for some rare cases), it's not supposed to be used by end users
+ // a real user should never use loopback/private/external as their host names
+ hl = ParseHostMatchList("", "loopback, [p]rivate")
+ cases = []tc{
+ {"loopback", nil, false},
+ {"", net.ParseIP("127.0.0.1"), true},
+ {"private", nil, true},
+ {"", net.ParseIP("192.168.1.1"), false},
+ }
+ test(cases)
+
+ hl = ParseSimpleMatchList("", "loopback, *.domain.com")
+ cases = []tc{
+ {"loopback", nil, true},
+ {"", net.ParseIP("127.0.0.1"), false},
+ {"sub.domain.com", nil, true},
+ {"other.com", nil, false},
+ {"", net.ParseIP("1.1.1.1"), false},
+ }
+ test(cases)
+
+ hl = ParseSimpleMatchList("", "external")
+ cases = []tc{
+ {"", net.ParseIP("192.168.1.1"), false},
+ {"", net.ParseIP("1.1.1.1"), false},
+ {"external", nil, true},
+ }
+ test(cases)
+
+ hl = ParseSimpleMatchList("", "")
+ cases = []tc{
+ {"", net.ParseIP("192.168.1.1"), false},
+ {"", net.ParseIP("1.1.1.1"), false},
+ {"external", nil, false},
+ }
+ test(cases)
+}
diff --git a/modules/hostmatcher/http.go b/modules/hostmatcher/http.go
new file mode 100644
index 00000000..c743f6ef
--- /dev/null
+++ b/modules/hostmatcher/http.go
@@ -0,0 +1,69 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package hostmatcher
+
+import (
+ "context"
+ "fmt"
+ "net"
+ "net/url"
+ "syscall"
+ "time"
+)
+
+// NewDialContext returns a DialContext for Transport, the DialContext will do allow/block list check
+func NewDialContext(usage string, allowList, blockList *HostMatchList) func(ctx context.Context, network, addr string) (net.Conn, error) {
+ return NewDialContextWithProxy(usage, allowList, blockList, nil)
+}
+
+func NewDialContextWithProxy(usage string, allowList, blockList *HostMatchList, proxy *url.URL) func(ctx context.Context, network, addr string) (net.Conn, error) {
+ // How Go HTTP Client works with redirection:
+ // transport.RoundTrip URL=http://domain.com, Host=domain.com
+ // transport.DialContext addrOrHost=domain.com:80
+ // dialer.Control tcp4:11.22.33.44:80
+ // transport.RoundTrip URL=http://www.domain.com/, Host=(empty here, in the direction, HTTP client doesn't fill the Host field)
+ // transport.DialContext addrOrHost=domain.com:80
+ // dialer.Control tcp4:11.22.33.44:80
+ return func(ctx context.Context, network, addrOrHost string) (net.Conn, error) {
+ dialer := net.Dialer{
+ // default values comes from http.DefaultTransport
+ Timeout: 30 * time.Second,
+ KeepAlive: 30 * time.Second,
+
+ Control: func(network, ipAddr string, c syscall.RawConn) error {
+ host, port, err := net.SplitHostPort(addrOrHost)
+ if err != nil {
+ return err
+ }
+ if proxy != nil {
+ // Always allow the host of the proxy, but only on the specified port.
+ if host == proxy.Hostname() && port == proxy.Port() {
+ return nil
+ }
+ }
+
+ // in Control func, the addr was already resolved to IP:PORT format, there is no cost to do ResolveTCPAddr here
+ tcpAddr, err := net.ResolveTCPAddr(network, ipAddr)
+ if err != nil {
+ return fmt.Errorf("%s can only call HTTP servers via TCP, deny '%s(%s:%s)', err=%w", usage, host, network, ipAddr, err)
+ }
+
+ var blockedError error
+ if blockList.MatchHostOrIP(host, tcpAddr.IP) {
+ blockedError = fmt.Errorf("%s can not call blocked HTTP servers (check your %s setting), deny '%s(%s)'", usage, blockList.SettingKeyHint, host, ipAddr)
+ }
+
+ // if we have an allow-list, check the allow-list first
+ if !allowList.IsEmpty() {
+ if !allowList.MatchHostOrIP(host, tcpAddr.IP) {
+ return fmt.Errorf("%s can only call allowed HTTP servers (check your %s setting), deny '%s(%s)'", usage, allowList.SettingKeyHint, host, ipAddr)
+ }
+ }
+ // otherwise, we always follow the blocked list
+ return blockedError
+ },
+ }
+ return dialer.DialContext(ctx, network, addrOrHost)
+ }
+}